Method and system for manufacturing solar cells and shingled solar cell modules

ABSTRACT

The present disclosure provides a method and system for manufacturing solar cells and shingled solar cell modules. The method as provided by the present disclosure includes performing scribing and dividing of the solar cells, sorting the obtained solar cell strips, and packaging the cell strips in the solar cell manufacturing process. The solar cell strips can be assembled directly after dismantling the package in the solar module manufacturing process. Therefore, the method can accomplish a smooth flow of manufacturing solar cells and shingled solar cell modules, reduce repeated processing steps, lower the risk of cracking and costs thereof, and optimize the current matching and the color consistency of the cell strips in the shingled solar cell modules.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser.No. 16/553,111, filed Aug. 27, 2019, which is a continuation ofInternational Application No. PCT/CN2018/119526, filed on Dec. 6, 2018,which claims priority from Chinese Application No. 201811410350.X, filedon Nov. 23, 2018. All of the abovementioned applications are herebyincorporated by reference in their entirety.

FIELD

The present disclosure generally relates to the field of manufacturingand application of crystalline silicon shingled solar cell modules, andmore specifically, to a method and system for manufacturing solar cellsand shingled solar cell modules.

BACKGROUND

With rapid technological progress and economic development in the globalrange, traditional fossil fuels, such as coal, oil, natural gas, and thelike, are depleting at a rapid pace, causing deterioration of theecological environment, and there arises a need of demanding more cleanenergy sources, accordingly. Due to excellent performance inreliability, safety, wide application, environment-friendliness andadequacy, the solar energy has become one of the most importantrenewable resources, and the solar (photovoltaic) industry has gainedwidespread global popularity in many countries and areas.

The solar cell is a device for converting light energy into electricalenergy as a result of photoelectric effect, the most common example ofwhich is a crystalline silicon cell. Given that the solar module is acore component for photovoltaic power generation, it is a trend todevelop efficient modules for improving the conversion efficiency. Ascompared with the legacy solar module, a shingled solar cell module,which is an efficient, dense shingling-technology based solar module,allows a bus bar at a front side of a cell to overlap the counterpart ata back side of a further cell, in a fashion of interconnecting the solarcells more closely, thereby minimizing the gaps between cells andreducing the inefficient space for power generation resulting from thegaps between cells. Therefore, it is possible to place more cells in thesame area, enlarge the light absorption area, and improve the conversionefficiency of the solar module.

A shingled solar cell module is typically formed by scribing a solarcell and dividing the solar cell into strips and bonding the same withconductive adhesive and then encapsulating them. The existing shingledsolar cell module of prior art is typically manufactured through thelegacy process flow of solar cells and modules. That is, in a cellmanufacturing process of a solar cell factory, the entire cell isproduced, and in a module manufacturing process of a solar modulefactory, the solar cell is scribed and divided into cell strips, and thecell strips are encapsulated into a shingled solar cell module through ashingling procedure. This process flow is unable to meet requirements onefficient sorting, and brings about repeated testing. The main reasonlies in the inconsistencies of the cell strips resulting from intra-celldifferences during the cell manufacturing process. Thus, in addition totesting and sorting performed for the entire sheet of the cell duringthe cell manufacturing process, a cell strip sorting step is required inthe module manufacturing process. The repeated testing and sorting causehigh labor intensity, higher costs and an increasing cracking risk.

Accordingly, there is a need of improving the method and system formanufacturing solar cells and shingled solar cell modules.

SUMMARY

In view of the problems existing in the prior art, the presentdisclosure provides a method and system for manufacturing solar cellsand shingled solar cell modules.

In an aspect, the present disclosure provides a method of manufacturinga solar cell, wherein, the method comprises: scribing the solar cell anddividing the solar cell into a plurality of solar cell strips in a cellmanufacturing process, and testing and sorting the plurality of solarcell strips in the cell manufacturing process.

According to a preferable embodiment of the present disclosure, themethod comprises:

a pretreatment step, in which a wafer is pretreated;a screen-printing step, in which a precious metal paste isscreen-printed on a surface of the pretreated wafer;a sintering and curing step, in which the screen-printed wafer issintered and cured to form a solar cell;a scribing and dividing step, in which the solar cell is scribed anddivide into a plurality of solar cell strips; anda post-treatment step, in which the plurality of solar cell strips arepost-treated respectively.

According to a preferable embodiment of the present disclosure, thepretreatment step comprises:

a texturization step, in which the surfaces of the wafer are textured;a junction diffusion step, in which the wafer is junction diffused toform PN junctions in the wafer;an etching step, in which the PN junctions at edges of the wafer areremoved by etching; anda coating step, in which one or more anti-reflection films are depositedon a front side of the wafer, and a back passivation film is depositedon a back side of the wafer.

According to another preferable embodiment of the present disclosure,the pretreatment step comprises:

a texturization step, in which the surfaces of the wafer are textured;anda coating step, in which amorphous silicon is deposited on surfaces ofthe wafer, and a transparent conductive oxide film is deposited onsurfaces of the amorphous silicon.

According to a further preferable embodiment of the present disclosure,the pretreatment step comprises:

a texturization step, in which the surfaces of the wafer are textured;a junction diffusion step, in which a p-type layer is diffused in afront side of the wafer to form PN junctions in the wafer;an etching step, in which the p-type layer at a back side and edges ofthe wafer and impurities on the surfaces of the wafer formed duringjunction diffusion are removed by etching;a tunnel oxide layer and multicrystalline silicon layer preparing step,in which a silicon dioxide layer is formed on the back side of thewafer, and a multicrystalline silicon layer is formed on the silicondioxide layer;an ion implanting step, in which phosphorus atoms are implanted, by ionimplanting, into the multicrystalline silicon layer;an annealing step, in which the implanted phosphorus atoms are activatedby annealing; anda coating step, in which a first layer of film is deposited on the frontside of the wafer, and then a second layer of film is deposited on thefront and back sides of the wafer.

According to a preferable embodiment of the present disclosure, residueliquid from the texturization step is cleaned before the junctiondiffusion step.

According to a preferable embodiment of the present disclosure, the PNjunctions formed at the edges of the wafer are removed at the etchingstep by plasma etching.

According to a preferable embodiment of the present disclosure, siliconphosphate glass on surfaces of the wafer formed at the junctiondiffusion step is removed before the coating step.

According to a preferable embodiment of the present disclosure, theanti-reflection film comprises a silicon nitride anti-reflection film.

According to a preferable embodiment of the present disclosure, residueliquid from the texturization step is cleaned before the coating step.

According to a preferable embodiment of the present disclosure, surfacesof the wafer are cleaned with a chemical solution before the coatingstep.

According to a preferable embodiment of the present disclosure, borontribromide is diffused on the front side of the wafer at the junctiondiffusion step to form a p-type layer.

According to a preferable embodiment of the present disclosure, etchingis performed with acid at the etching step, and the impurities areborosilicate glass.

According to a preferable embodiment of the present disclosure, thesilicon dioxide layer has a thickness of 1 nm-2 nm, and themulticrystalline silicon layer has a thickness of 100 nm-200 nm.

According to a preferable embodiment of the present disclosure, thefirst layer of film is an aluminum oxide film, and the second layer offilm is a silicon nitride film.

According to a preferable embodiment of the present disclosure, thepost-treatment step comprises performing testing and sorting andappearance inspection on the plurality of solar cell strips.

According to a preferable embodiment of the present disclosure, thescribing and dividing step comprises physical scribing and chemicalscribing.

According to a preferable embodiment of the present disclosure, thescribing and dividing step comprises laser scribing.

According to a preferable embodiment of the present disclosure, thescribing and dividing step comprises linear scribing.

According to a preferable embodiment of the present disclosure, laserscribing is performed at a side of the solar cell away from the surfacehaving the PN junctions.

According to a preferable embodiment of the present disclosure, thetesting and sorting comprise an electrical performance testing and anelectroluminescence testing.

According to a preferable embodiment of the present disclosure, theappearance inspection comprises an appearance visual testing and colorsorting.

According to a preferable embodiment of the present disclosure, thesolar cell strips are graded after post-treated.

In another aspect, the present disclosure provides a method ofmanufacturing a shingled solar cell module, the method comprises:

receiving the solar cell strips manufactured with the method accordingto the above embodiments; andforming, by a shingling process, the shingled solar cell module from thesolar cell strips.

In a further aspect, the present disclosure provides a system formanufacturing a solar cell, the system comprises:

pretreatment devices for pretreating a wafer;a screen-printing device for receiving the wafer output by thepretreatment devices, and screen-printing a precious metal paste ontosurfaces of the pretreated wafer;a sintering and curing device for receiving the wafer output by thesintering and curing device, and sintering and curing the wafer to formthe solar cell;a scribing and dividing device for receiving the solar cell output bythe sintering and curing device, and scribing and dividing the solarcell to form a plurality of solar cell strips; andpost-treatment devices for receiving the plurality of solar cell stripsoutput by the scribing and dividing device, and post-treating theplurality of solar cell strips, respectively.

According to a preferable embodiment of the present disclosure, thepretreatment devices comprise:

a texturization device for texturizing the surfaces of the wafer;a junction diffusion device for receiving the wafer output by thetexturization device, and junction diffusion the wafer to form PNjunctions therein;an etching device for receiving the wafer output by the junctiondiffusion device, and removing, by etching, the PN junctions at edges ofthe wafer; anda coating device for receiving the wafer output by the etching device,depositing one or more anti-reflection films on a front side of thewafer, and depositing a back passivation film on a back side of thewafer.

According to a preferable embodiment of the present disclosure, thepretreatment devices comprise:

a texturization device for texturizing the surfaces of the wafer; anda coating device for receiving the wafer output by the texturizationdevice, depositing amorphous silicon on the surfaces of the wafer, anddepositing a transparent conductive oxide film on surfaces of theamorphous silicon.

According to a preferable embodiment of the present disclosure, thepretreatment devices comprise:

a texturization device for texturizing the surfaces of the wafer;a junction diffusion device for receiving the wafer output by thetexturization device, and diffusion a p-type layer on a front surface ofthe wafer to form PN junctions in the wafer;an etching device for receiving the wafer output by the junctiondiffusion device, and removing the p-type layer at a back side and edgesof the wafer and impurities on the surfaces of the wafer formed in thejunction diffusion device;a tunnel oxide layer and multicrystalline silicon layer preparing devicefor receiving the wafer output by the etching device, forming a silicondioxide layer on the back side of the wafer, and forming amulticrystalline silicon layer on the silicon dioxide layer;an ion implanting device for receiving the wafer output by the tunneloxide layer and multicrystalline silicon layer preparing device, andimplanting phosphorus atoms into the multicrystalline silicon layer;an annealing device for receiving the wafer output by the ion implantingdevice, and activating the implanted phosphorus atoms by annealing; anda coating device for receiving the wafer output by the annealing device,depositing a first layer of film on a front side of the wafer, and thendepositing a second layer of film on the front side and back side of thewafer.

According to a preferable embodiment of the present disclosure, thepost-treatment devices comprise a device for performing testing andsorting on the plurality of solar cell strips, and a device forappearance inspection.

According to a preferable embodiment of the present disclosure, thescribing and dividing device comprises physical scribing device andchemical scribing device.

According to a preferable embodiment of the present disclosure, thescribing and dividing device comprises laser scribing device.

According to a preferable embodiment of the present disclosure, thescribing and dividing device comprises linear scribing device.

According to a preferable embodiment of the present disclosure, thescribing and dividing device performs laser scribing at one side of thesolar cell away from the PN junctions.

According to a preferable embodiment of the present disclosure, theetching device comprises plasma etching device.

According to a preferable embodiment of the present disclosure, theanti-reflection film comprises a silicon nitride anti-reflection film.

According to a preferable embodiment of the present disclosure, theetching device comprises acid etching device.

According to a preferable embodiment of the present disclosure, thetunnel oxide layer and multicrystalline silicon layer preparing devicecomprises a low pressure chemical vapor deposition device for forming asilicon dioxide layer with a thickness of 1 nm-2 nm on the back side ofthe wafer, and a multicrystalline silicon layer with a thickness of 100nm-200 nm on the silicon dioxide layer.

According to a preferable embodiment of the present disclosure, thecoating device deposits an aluminum oxide film on the front side of thewafer, and then depositing a silicon nitride film on the front and backsides of the wafer.

According to a preferable embodiment of the present disclosure, thedevice for performing testing and sorting on the plurality of solar cellstrips comprises electrical performance testing device andelectroluminescence testing device.

According to a preferable embodiment of the present disclosure, thedevice for performing appearance inspection on the plurality of solarcell strips comprises appearance visual testing device and color sortingdevice.

The method of manufacturing a solar cell and a solar module as providedby the present disclosure includes performing scribing and dividing ofthe solar cells, sorting the obtained solar cell strips, and packagingthe cell strips in the cell manufacturing process. The cell strips canbe shingling assembled directly after dismantling the package in themodule manufacturing process. Hence, the method can accomplish a smoothflow of manufacturing the solar cells and the shingled solar cellmodules, reduce repeated processing steps, lower the cracking risk andcosts thereof, and optimize the current matching and the appearancecolor consistency of the cell strips in the shingled solar cell modules.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a method of manufacturing a solar cell according to apreferable embodiment of the present disclosure.

FIG. 2A illustrates a pretreatment step of manufacturing a solar cellaccording to a preferable embodiment of the present disclosure.

FIG. 2B illustrates a pretreatment step of manufacturing a solar cellaccording to another preferable embodiment of the present disclosure.

FIG. 2C illustrates a pretreatment step of manufacturing a solar cellaccording to a further preferable embodiment of the present disclosure.

FIG. 3 illustrates a method of manufacturing a shingled solar cellmodule according to a preferable embodiment of the present disclosure.

FIG. 4 illustrates a system for manufacturing a solar cell according toa preferable embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, the method and system for manufacturing solar cells andshingled solar cell modules according to the present disclosure will bedescribed in detail with reference to the accompanying drawings. Theembodiments described herein are the preferable embodiments according tothe present disclosure, and those skilled in the art would envision, onthe basis of the preferable embodiments described, other manners capableof implementing the present disclosure, which also fall within the scopeof the present disclosure.

FIG. 1 illustrates a method of manufacturing a solar cell according to apreferable embodiment of the present disclosure. As shown, the methodmainly includes steps of pretreatment, screen-printing, sinteringcuring, scribing and dividing, and post-treatment. Wherein, thepretreatment step may be varied with different types of cells, and forconventional cells, the pretreatment step, as shown in FIG. 2A, mainlyincludes:

A texturization step: the surfaces of a monocrystalline/multicrystallinesilicon wafer are textured to obtain a good texturization and thus thesurface area of the wafer is increased, so as to receive more photons(i.e., energy) while reducing reflection of the incident light.

Alternatively, the residue liquid generated during texturization can becleaned thereafter, to reduce impacts of acid and alkaline substances oncell junctions.

A junction diffusion step: through reaction of, for example, phosphorusoxychloride with the wafer, phosphorus atoms are obtained. Over a periodof time, the phosphorus atoms enter into the surface layer of the wafer,and form an interface between an n-type semiconductor and a p-typesemiconductor, by means of permeation and diffusion into the wafer viagaps between silicon atoms, or by means of ion implantation, and thejunction diffusion procedure is completed, thereby converting the lightenergy into the electric energy. It would be appreciated that othertypes of junction-making are also feasible.

Considering that a phosphosilicate glass layer may be formed on thewafer surface in the junction diffusion procedure, a phosphosilicateglass removal procedure is optional to reduce impacts on the efficiencyof the solar cell.

An etching step: given that a short circuit channel is formed byjunction diffusion at the wafer edges, photogenerated electronscollected at the front side of the PN junctions flow along the area atthe edge where phosphorous is diffused to the back side of the PNjunctions, causing short circuit. Therefore, it is required to removethe PN junctions at the edges by etching, for example, plasma etching,so as to avoid short circuit at the edges.

A coating step: in order to reduce surface reflection of the wafer andimprove the conversion efficiency, it is required to deposit one or morelayers of silicon nitride anti-reflection film on a surface at one sideof the wafer, and the anti-reflection film can be prepared by, forexample, plasma enhanced chemical vapor deposition (PEVCD) procedure.

In order to achieve a good passivation effect, a rear passivation filmmay be deposited on the surface at the opposite side of the cells toreduce the recombination of carriers.

The above pretreatment steps are described in connection with themanufacturing process of legacy solar cells. It would be appreciatedthat a corresponding preparation process can be employed as asubstitute, for other p-types, n-types, and other types of cells, forexample, an ordinary mono/multi crystalline silicon cell, a passivatedemitter rear contact (PERC) cell, a heterojunction (HJT) cell, a tunneloxide passivated contact (TopCon) cell or the like. For example, asshown in FIG. 2B, the pretreatment step in a manufacturing process of aheterojunction cell mainly include:

A texturization step: the surfaces of a monocrystalline/multicrystallinesilicon wafer are textured to obtain a good textured structure and thusincrease the surface area of the wafer, so as to receive more photonswhile reducing reflection of the incident light.

Alternatively, the residue liquid generated during texturization can becleaned thereafter, to reduce impacts of acid and alkaline substances onbattery junction.

A coating step: the amorphous silicon is deposited on both surfaces ofthe wafer, and then transparent conductive oxide (TCO) films aredeposited on the surfaces of the amorphous silicon respectively.

A preparation process of a tunnel oxide passivated contact (TopCon)cell, as shown in FIG. 2C, mainly includes:

A texturization step: the surfaces of a monocrystalline/multicrystallinesilicon wafer is textured to obtain a good textured structure and thusincrease the surface area of the wafer, so as to receive more photons(i.e., energy) while reducing reflection of the incident light.

A junction diffusion step: at a high temperature, boron tribromide isdiffused to the wafer surfaces to form a p-type layer, and further formPN junctions in the wafer.

An etching step: the p-type layer at the back side and the edges of thewafer formed in the junction diffusion step is etched using an acidsolution of a certain concentration. In the meantime, impurities, forexample, borosilicate glass, on the wafer surfaces formed during thejunction diffusion process are removed as well.

A tunnel oxide layer and multicrystalline silicon layer preparing step:in low pressure chemical vapor deposition device, an ultrathin silicondioxide layer is formed on the back side of the wafer by thermaloxidation, which has a thickness of about 1 nm-2 nm (e.g. 1.5 nm), andthen, a multicrystalline silicon layer mixed with an amorphous siliconphase and a microcrystalline silicon phase is formed on the silicondioxide layer, with a thickness of about 100 nm-200 nm (e.g. 150 nm).

An ion implantation step: phosphorus atoms are implanted into themulticrystalline silicon layer in an ion implantation manner.

An annealing step: the implanted phosphorus atoms are activated by ahigh temperature annealing process, when the amorphous phase and themicrocrystalline phase in the multicrystalline silicon layer areconverted into a multicrystalline phase.

An optional cleaning step: a chemical solution may be used optionally toclean the wafer surfaces.

A coating step: a film for passivation, for example, aluminum oxidefilm, is deposited over the wafer surfaces, using an atom layerdeposition (ALD) method, and then, a further film is deposited on thefront and back sides of the wafer by plasma enhanced chemical vapordeposition (PECVD), to reduce reflection and protect the film forpassivation at the front side of the wafer while performing passivationat the back side, and the further film may be a silicon nitride film.

The pretreatment step of the method according to the present disclosureis described above, and other steps thereof will be described below.

A screen-printing step: upon completion of the above process steps,photogenerated positive and negative carriers are generated, and then,it is required to collect the photogenerated carriers. A precious metalpaste (e.g. silver paste, aluminum paste or the like) may be printed,for example, by screen-printing or the like, onto the pretreated waferaccording to a particular solar cell metalizing pattern.

A sintering and curing step: the screen-printed wafer is sintered andcured at a high temperature, to achieve efficient ohmic contact andfurther form a solar cell.

A scribing and dividing step: the entire sheet of the sintered solarcell is subjected to laser scribing and dividing into a plurality ofstrips. Of course, the scribing according to the present disclosure maybe any appropriate physical or chemical scribing, for example, laserscribing. Specifically, the sintered solar cells are transferred to adetection position for appearance inspection, and the solar cells with agood appearance are subjected to visual positioning while those solarcells with a poor appearance are automatically shunted to a NG (notgood) position. A multi-track scriber & buffer, or a preset buffer-stackarea may be provided according to the production pace, to accomplish acontinuous operation. In addition, parameters of the laser device mayalso be set according to the optimum scribing and dividing effect, toobtain a quick scribing speed, a narrow heat-affected zone and a narrowscribing line width, better uniformity, a predetermined scribing depth,and the like. Subsequent to automatic scribing, dividing the solar atthe scribing positions by an automatic dividing mechanism of the laserscribing machine, then forming a plurality of solar cell strips. It isworth noting that, in order to avoid leakage current caused by thedamaged PN junctions in the scribing and dividing process, a surfaceaway from the PN junction side is preferably selected as a laserscribing surface, and therefore, a separate 180-degree reversing devicemay be further provided to adjust the orientation of the front and backsides of the cell.

A post-treatment step: the post-treatment step may include:

A testing and sorting step: the solar cell strips may enter sequentiallyinto testing units, for example, including an electrical performance(IV) testing unit, an electroluminescence (EL) testing unit, anappearance visual (VI) testing unit, and the like, to implement testingand sorting on individual cell strips.

Alternatively, color sorting may be performed for the solar cell stripsafter the testing and sorting step.

Subsequent to the above steps, the solar cell strips having been testedand sorted can be packed and stored according to different grades. Aftersolar cell strips are manufactured using the method according to thepresent disclosure, shingled solar cell modules can be obtained byassembling them in a shingling process. FIG. 3 illustrates a method ofmanufacturing solar modules according to a preferable embodiment of thepresent disclosure, which mainly includes steps of:

receiving solar cell strips manufactured with the method according tothe embodiment as described above; andmanufacturing shingled solar cell modules from the solar cell strips ina shingling process.

Specifically, as shown in FIG. 3, upon receiving the solar cell stripswhich have been scribed, split cut, tested and sorted, a shingled solarcell module production plant can directly feed the solar cell stripsaccording to their grades, thereby completing manufacturing andpackaging of the shingled solar cell modules. Taking a single glassmetal frame assembly as an example, the method includes, for example,laminated soldering (soldering lead wires, bus bars and the like),adhesive film and backplane laying (EVA/TPT laying), inspection prior tolamination (including, for example, EL inspection, VI inspection, andthe like), lamination, mounting and curing (including, for example,mounting a frame, mounting a junction box, curing, and the like),testing inspection (including, for example, an IV testing, an ELtesting, an appearance testing, and the like). It would be appreciatedthat the process of manufacturing typical shingled solar cell modulesdescribed above is only as an example, and the method according to thepresent disclosure is also applicable to manufacture other shingledsolar cell modules.

FIG. 4 illustrates a system for manufacturing solar cells according to apreferable embodiment of the present disclosure. As shown, the systemmainly includes pretreatment devices, a screen-printing device, asintering and curing device, a scribing and dividing device andpost-treatment devices. Wherein, for different types of solar cells, thedevices may include different pretreatment devices, and for a typicalcell, the pretreatment devices mainly include the following devices.

Texturization device is provided for texturizing the surfaces of amonocrystalline/multicrystalline silicon wafer to obtain a good texturedstructure and thus increase the surface area of the wafer, so as toreceive more photons (energy) while reducing reflection of the incidentlight.

Junction diffusion device is provided for receiving the wafer output bythe texturization device, and obtaining phosphorus atoms throughreaction of, for example, phosphorus oxychloride with the wafer. Over aperiod of time, the phosphorus atoms enter into the surfaces of thewafer and form an interface between an n-type semiconductor and a p-typesemiconductor, by means of permeation and diffusion into the wafer viagaps between silicon atoms, or by means of ion implantation, thejunction diffusion procedure is accomplished, thereby converting thelight energy into the electric energy. It would be appreciated thatother types of junction-making are also feasible.

Given that a short circuit channel is formed by junction diffusion atthe wafer edges, photogenerated electrons collected at the front sideflow along the area at the edges where phosphorous is diffused to theback side, causing short circuit. Therefore, it is required to removethe PN junctions at the edges by etching, for example, plasma etching,so as to avoid short circuit at the edges.

Coating device is provided. In order to reduce surface reflection of thewafer and improve the conversion efficiency, it is required to depositone or more layers of silicon nitride anti-reflection film on a surfaceat one side of the wafer, and the anti-reflection film can be preparedby, for example, plasma enhanced chemical vapor deposition (PEVCD)procedure. In order to achieve a good passivation effect, a backpassivation film may be deposited on the opposite surface at the otherside of the cell to reduce the recombination of carriers.

The above pretreatment devices are described in connection with theprocess of manufacturing typical solar cells. It would be appreciatedthat other corresponding pretreatment devices may be employed assubstitutes, for other p-types, n-types, and other types of cells, forexample, an ordinary mono/multicrystalline silicon cell, a passivatedemitter rear contact (PERC) cell, a heterojunction (HJT) cell, a tunneloxide passivated contact (TopCon) cell or the like. For example, asshown in FIG. 2B, the pretreatment devices involved in a manufacturingprocess of the heterojunction cell mainly include:

Texturization device is provided for texturizing the surfaces of themonocrystalline/multicrystalline silicon wafer to obtain a good texturedstructure and thus increase the surface area of the wafer, so as toreceive more photons while reducing reflection of the incident light.

Coating device is provided for receiving the wafer output by thetexturization device, depositing amorphous silicon on both surfaces ofthe wafer, and depositing a transparent conductive oxide (TCO) film onthe amorphous silicon surfaces.

The pretreatment devices involved in a preparation process of a tunneloxide passivated contact (TopCon) cell, as shown in FIG. 2C, mainlyinclude:

Texturization device is provided for texturizing the surfaces of themonocrystalline/multicrystalline silicon wafer to obtain a good texturedstructure and thus increase the surface area of the wafer, so as toreceive more photons (i.e., energy) while reducing reflection of theincident light.

Junction diffusion device is provided for receiving the wafer output bythe texturization device, diffusion, at a high temperature, borontribromide into the wafer surfaces to form a p-type layer, and furtherforming PN junctions in the wafer.

Etching device is provided for receiving the wafer output by thejunction diffusion device, and etching the p-type layer at the back sideand the edges of the wafer formed in the junction diffusion step, usingan acid solution of a certain concentration, while removing impurities,for example, borosilicate glass, on the wafer surfaces formed during thejunction diffusion process.

A tunnel oxide layer and multicrystalline silicon layer preparing deviceis provided for receiving the wafer output by the etching device,forming an ultrathin silicon dioxide layer on the back side of the waferby thermal oxidation, which has a thickness of about 1 nm-2 nm (e.g. 1.5nm), and then forming a multicrystalline silicon layer mixed with anamorphous phase and a microcrystalline phase on the silicon dioxidelayer, which has a thickness of about 100 nm-200 nm (e.g. 150 nm).

Ion implanting device is provided for receiving the wafer output by thetunnel oxide layer and multicrystalline silicon layer preparing device,and implanting phosphorus atoms into the multicrystalline silicon layerin an ion implantation manner.

Annealing device is provided for receiving the wafer output by the ionimplanting device, activating the implanted phosphorus atoms by a hightemperature annealing process, while the amorphous phase and themicrocrystalline phase in the multicrystalline silicon layer areconverted into a multicrystalline phase.

Coating device is provided for receiving the wafer output by theannealing device, depositing a film for passivation, for example,aluminum oxide film, over the wafer surfaces, using an atom layerdeposition (ALD) method, and then depositing, during preparation, afurther film over the front and back sides of the wafer by plasmaenhanced chemical vapor deposition (PECVD), to reduce reflection andprotect the film for passivation at the front side of the wafer whenperforming passivation at the rear side, and the further film may be asilicon nitride film.

The pretreatment devices for implementing the method according to thepresent disclosure are described above, and other devices thereof willbe described below.

A screen-printing device is provided for receiving the wafer output bythe pretreatment devices. Having been processed by the above device, thewafer can generate photogenerated positive and negative carriers, andthen, it is required to collect the photogenerated carriers. A preciousmetal paste (e.g. silver paste, aluminum paste or the like) may beprinted, for example, by screen-printing or the like, onto thepretreated wafer according to a particular solar cell metalizingpattern.

A sintering and curing device is provided for receiving the wafer outputby the screen-printing device, and sintering and curing thescreen-printed wafer at a high temperature, to achieve efficient ohmiccontact and further form a solar cell.

A scribing and dividing device is provided for receiving the waferoutput by the sintering and curing device, and laser scribing anddividing the entire sheet of the sintered solar cell into a plurality ofstrips. Of course, the scribing according to the present disclosure maybe any appropriate physical or chemical scribing, for example, laserscribing. Specifically, the sintered solar cells go to a detectionposition for appearance inspection, and the OK cells with a goodappearance inspection result are subjected to visual positioning whilethose cells with a poor appearance inspection result are automaticallyshunted to a NG (not good) position. A multi-track scriber & buffer, ora preset buffer-stack area may be provided according to the productionpace, to accomplish a continuous operation. In addition, parameters ofthe laser device may also be set according to the optimum scribing anddividing effect, to obtain a quick scribing speed, a narrowheat-affected zone and a narrow scribing line width, better uniformity,a predetermined scribing depth, and the like. Subsequent to automaticscribing, dividing the solar cell at the scribing positions by anautomatic dividing mechanism of the laser scribing machine, then forminga plurality of solar cell strips. It is worth noting that, in order toavoid leakage current caused by the damaged PN junctions in the scribingand dividing process, a surface away from the PN junction side ispreferably selected as a laser scribing surface, and therefore, aseparate 180-degree reversing device may be further provided to adjustthe orientation of the front and back sides of the cell.

The post-treatment devices may include:

A testing and sorting device is provided. The solar cell strips mayenter sequentially into testing units, for example, including anelectrical performance (IV) testing unit, an electroluminescence (EL)testing unit, an appearance visual (VI) testing unit, and the like, toimplement testing and sorting on individual cell strips.

Alternatively, color sorting device may include appearance visual (VI)testing device and color sorting device. From the above embodiments, itcan be obtained that the method of manufacturing solar cells andshingled solar cell modules, and the device for manufacturing the solarcells according to the present disclosure involve performing scribingand dividing in the cell manufacturing process, then testing and sortingthe cell strips, and the module production plant can performingshingling assembling directly after receiving the cell strips in themodule manufacturing process. Hence, the method can accomplish a smoothflow of manufacturing the solar cells and the shingled solar cellmodules, and reduce repeated processing steps.

The protection scope of the present disclosure is only defined by theappended claims. Given the teaching of the present disclosure, thoseskilled in the art will envision that the structure disclosed herein canbe replaced by feasible substitutes, and the embodiments disclosedtherein can be combined to form new embodiments which likewise fallwithin the scope of the appended claims.

What is claimed is:
 1. A method of manufacturing a solar cellcomprising: pretreating a wafer, by: texturing one or more surfaces ofthe wafer; diffusing a p-type layer on a front side of the wafer to formPN junctions in the wafer; removing the p-type layer at a back side andedges of the wafer and impurities on surfaces of the wafer formed duringthe junction diffusion by etching; forming a silicon dioxide layer onthe back side of the wafer; forming a multicrystalline silicon layer onthe silicon dioxide layer; implanting phosphorus atoms into themulticrystalline silicon layer by ion implanting; activating thephosphorus atoms implanted by annealing; and depositing a first layer offilm on the front side of the wafer, and a second layer of film on thefront and back sides of the wafer; screen-printing a precious metalpaste on a surface of the pretreated wafer; sintering and curing thescreen-printed wafer to form a solar cell; performing laser scribing ata side of the solar cell away from a surface of the solar cell havingthe PN junctions and dividing the solar cell into a plurality of solarcell strips; and performing testing, appearance inspection, and sortingon the plurality of solar cell strips respectively in the cellmanufacturing process, wherein the sorting of the plurality of solarcell strips is based upon a result of the testing.
 2. The methodaccording to claim 1, characterized in that the testing comprises anelectrical performance testing and an electroluminescence testing. 3.The method according to claim 1, characterized in that the appearanceinspection comprises an appearance visual testing and color sorting. 4.The method according to claim 1, wherein sorting the plurality of solarcell strips comprises sorting the solar cell strips into a plurality ofdifferent grades, based upon the result of the testing.
 5. A method ofmanufacturing a shingled solar cell module, characterized by comprisingsteps of: receiving the solar cell strips manufactured with the methodaccording to claim 1; and forming, by a shingling process, the shingledsolar cell module from the solar cell strips.